Mixing cartridge



FIG. 1 is a top perspective view showing our new design;

FIG. 2 is a left side elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a rear elevational view thereof; and,

FIG. 6 is a front elevational view thereof.

The broken lines in the drawings depict unclaimed environmental subject matter. 

The ornamental design for a mixing cartridge, as shown and described. 